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  #61  
Old 02-14-2014, 12:22 PM
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Re: SVX can't climb hills

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Originally Posted by gwynethh View Post
So you have an existing broken connector for a vac hose of unknown service. Should this be eliminated as a (very unlikely) cause before digging into the cats/o2 sensors? Agree it doesn't seem likely but it is a defect staring you in the face that can be struck off the list rather easily.
I would love to, but I'm not even sure what that hose goes to. The general idea so far is that it connects to the purge solenoid. On top of that though, there's nothing I can do about it right now since I can't see any way of replacing that without the manifold coming off, which won't be until I get her home.

So the best I can do right now is seal the vacuum leak
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  #62  
Old 02-14-2014, 07:41 PM
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Re: SVX can't climb hills

If it's the hose that you think it is, you'll just be losing the IRIS valve's function. This shouldn't cause the "lay down" you're experiencing going up hills.

Bill
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  #63  
Old 02-16-2014, 02:48 PM
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Re: SVX can't climb hills

I went for a little test drive today. I've gone about 40 miles of mostly highway speeds with very little flogging. Went towards the mountains and drove some of the hills with no gas cap.

I can say that the gas cap is not the issue, since I'm sitting in a parking lot somewhere in New York waiting for e problem to subside so I can make it home.

It was very gradual this time. at first, it seemed to not want to downshift until I put my foot down a little farther.

Then it had a slight hiccup at a stop sign a few miles later. About 3 miles after that, there was no power past half throttle. By the time I pulled over, it was angry just to idle.

I got a garage to use this week, so I should be able to take the O2 sensors out and see the flow from both sides. Can I clean the O2 sensors while they are out?

Thanks again for the help, guys. I'm just going to chill out here until she wants to run again. I wonder what CDs I have.... *finds the only CD is Creedence Live*... Damn it.
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  #64  
Old 02-16-2014, 03:48 PM
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Re: SVX can't climb hills

I made it home. I sat for around 15 minutes with the engine off, but it wasn't solving the problem, so I started it and let it idle for a few minutes. It ran rather rough and then got worse with a lot of shaking and bucking while in park, but it soon smoothed off and the idle went from around 400 rpm back to around 750 rpm. It took about 30 seconds to smooth out, but it was golden for the ten miles or so home.

It started to cough again when I got home, but it went away as I pulled into the lot.

Another theory: if the fuel is contaminated with anything, it takes a while for the pump to agitate it and spread it around. Once it settles again and I let it idle through whatever is in the lines, the world is good again. That would explain why it died immediately after filling up last weekend. This would also explain why it wants to die under sudden load if the pump varies pressure depending upon throttle condition. With a higher input, the pump kicks more fuel around in the tank along with any water or such.

Now, the specific gravity of gasoline should be around 70% of water's, making water heavier and sinking to the bottom of the tank. If our tanks have drain plugs like the Legacy tanks do, then if I crack them open and inspect whatever comes out, it should tell me a tale.

If I pursue this theory, I'd probably temporarily replace the fuel filter with a transparent universal one just to see what is going through those lines.

Thoughts?

-Randy
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  #65  
Old 02-16-2014, 04:17 PM
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Re: SVX can't climb hills

Glad to hear it hasn't left you stranded completely...A little Fogarty brothers and you were good to go !! Has anybody confirmed the presence or lack of a gas tank drain yet. Since it's made out of plastic I get the feeling there might not be a drain fitting if I had to guess. Also no expert (me) on whether an O2 sensor likes carb/brake cleaner soaking. I have taken off the perf'd metal cover on an old sensor out of curiousity and the cylindrical part underneath only had a light coating of carbon which wiped off easily. Didn't look like it was prone to gunking up like an EGR.

If after your other checks (removing sensors, et. al) you could remove the rear bottom seat (easy 2 tabs) and remove the fuel pump sheet metal access cover so as to suck out the tanks contents once you get it as empty as you can after driving it. Harbor Freight has those cheap pumps that might tolerate gas for a while (made for oil/antifreeze and "gas" on label but I have my doubts re: the latter fluid not destroying it after a while--I have one that I used for tranny fluid and engine oil). When as empty as you can get it, you might what to pour in small amounts of fresh gas and resuction a few times.

Since the tank IS plastic would expect the rust/crud seen in metal, old tanks but I have been involved with gas fill ups that have sucked sand/water/crappola from near empty station reservoir tanks.

You didn't have a pissed off girl friend that decided to empty a few Mountain Dews in your tank !! Not likely unless she was so determined that she popped your gas flap. Had a friend who had a drunk "buddy" actually take a leak in his Mitsu Evo...ignore this last paragraph if you like..just an attempt to lighten your situation.

Good Luck










Quote:
Originally Posted by WhatIsThisIDont View Post
I made it home. I sat for around 15 minutes with the engine off, but it wasn't solving the problem, so I started it and let it idle for a few minutes. It ran rather rough and then got worse with a lot of shaking and bucking while in park, but it soon smoothed off and the idle went from around 400 rpm back to around 750 rpm. It took about 30 seconds to smooth out, but it was golden for the ten miles or so home.

It started to cough again when I got home, but it went away as I pulled into the lot.

Another theory: if the fuel is contaminated with anything, it takes a while for the pump to agitate it and spread it around. Once it settles again and I let it idle through whatever is in the lines, the world is good again. That would explain why it died immediately after filling up last weekend. This would also explain why it wants to die under sudden load if the pump varies pressure depending upon throttle condition. With a higher input, the pump kicks more fuel around in the tank along with any water or such.

Now, the specific gravity of gasoline should be around 70% of water's, making water heavier and sinking to the bottom of the tank. If our tanks have drain plugs like the Legacy tanks do, then if I crack them open and inspect whatever comes out, it should tell me a tale.

If I pursue this theory, I'd probably temporarily replace the fuel filter with a transparent universal one just to see what is going through those lines.

Thoughts?

-Randy
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  #66  
Old 02-16-2014, 04:28 PM
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Re: SVX can't climb hills

My doors don't lock (but that's a whole other can of worms) and there are some less than bright people around here, so there is a slight possibility that the fuel had a less than ideal additive thrown in, but This started after I filled up on SuperBowl sunday a few weeks ago, so a very bad tank of gas is more than possible.

So the service door for the fuel pump is under the back seat? I would think I would be able to pop that open and easily see what's floating around in there with my flashlight.
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  #67  
Old 02-16-2014, 06:00 PM
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Re: SVX can't climb hills

http://www.phantomotaku.com/SVX/MSA5...uel_system.pdf


Under the access plate is the fuel tank access cap...follow the above thread to see the workings here. The cap ring unscrews..special tool makes it easier but using a drift to turn the cap via the slots CCW will get things going after you disconnect the various hoses/electrical connector. The rubber gasket is usually reusable. Supposed to torque down the cap ring but don't see the spec. number. I'd just gain access enough to insert a pump's tubing since you can bugger things up if you yank the whole assembly out..fuel meters, etc.
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  #68  
Old 02-17-2014, 03:29 PM
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Re: SVX can't climb hills

For an alternative method, would I be able to just short the fuel pump relay, disconnect the fuel filter, and then just collect whatever comes out and inspect it? If I get discoloration and debris through the fuel, I would think I could fill it from whatever the pump empties and that would take me the trip home to where I can clean the tank out more properly.
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  #69  
Old 02-17-2014, 03:46 PM
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Re: SVX can't climb hills

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Originally Posted by WhatIsThisIDont View Post
For an alternative method, would I be able to just short the fuel pump relay, disconnect the fuel filter, and then just collect whatever comes out and inspect it? If I get discoloration and debris through the fuel, I would think I could fill it from whatever the pump empties and that would take me the trip home to where I can clean the tank out more properly.

You'd want the pump pumping, right? The pump should do it's thing with the key "ON". How about getting that HF pump and sticking the hose through the filler opening 'til it feels like it is bottoming out and seeing what comes out? Your suggestion would show non agitated gas where your theory about what happens when you go up hill wouldn't be shown.

Any chance to check those coils yet? Another idea..when the car is running poorly, stop with engine still running, and tap the MAF box with a screwdriver firmly a few times and see if it helps.
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  #70  
Old 02-17-2014, 04:11 PM
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Re: SVX can't climb hills

Couldn't get to the garage this weekend, but I should be good to get in some night this week, so I have a better chance of seeing those coils.

And good call on the gas. I hadn't thought of the agitation issue. This is why I ask you guys
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  #71  
Old 02-17-2014, 05:44 PM
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Re: SVX can't climb hills

My vote is still on the coils. The fuel issue sounds far fetched. Debris would plug the filter and other unwanted liquids would be present at almost all times. A few minutes of driving would mix everything up pretty well.

Anything is possible I guess.
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  #72  
Old 02-17-2014, 05:49 PM
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Re: SVX can't climb hills

if you want to check for water in fuel put a measured amount of water in a vial or bottle then fill it with your gas, shake it, and let it sit. the water will draw the other water out of your gas after they separate. if you have more water in the container then you put in then you have water in your gas.
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  #73  
Old 02-17-2014, 06:00 PM
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Re: SVX can't climb hills

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Originally Posted by Blacky View Post
My vote is still on the coils. The fuel issue sounds far fetched. Debris would plug the filter and other unwanted liquids would be present at almost all times. A few minutes of driving would mix everything up pretty well.

Anything is possible I guess.
I've never seen anything like this, and with the condition she was in when I bought her, just about anything I touch has a good chance to be bad. I'll check those resistances and check the driver side for arcing and burn marks whenever I get it in the garage.

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Originally Posted by 92snowmachine View Post
if you want to check for water in fuel put a measured amount of water in a vial or bottle then fill it with your gas, shake it, and let it sit. the water will draw the other water out of your gas after they separate. if you have more water in the container then you put in then you have water in your gas.
That's pretty genius. Thank's for the tip!
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  #74  
Old 02-21-2014, 03:40 AM
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Talking Re: SVX can't climb hills

Well, I'll take it that the root cause of the problem has yet to be identified. So, here we go with another "Hail Mary"..

In the world of computers, there used to be a saying... something about "GIGO. Garbage In, Garbage Out". Which basically means bad input yields bad output. The SVX was ahead of it's time, for it's time, the ECU, to the best of it's ability, learns and adapts. Unfortunately, it can only learn and adapt to the input it is given. Give it bad input, and it will give bad instructions to everything it controls. Even to the extent of mimicking an issue in a system that has none.

The worst things to diagnose are when a component is only sick, not dead, or, even worse, only intermittently sick. We've all had cars that stopped mis-behaving on the way to the shop for a repair appointment.

Let's tabulate the votes for various causes of this malady..

In no particular order, the contestants are..

Coil packs! ( and their associates, wiring boots and caps ).... Well, definitely a contender, the symptoms are there, but.. well.. It just seems that there wouldn't be such long periods of proper functionality, followed by such abysmal performance. Especially on such a random schedule.

Catalytic converter! Yup, absolutely, some of the symptoms are there. But also, some of the most common symptoms are missing. No cherry red glow, no smell of rotten eggs, and, most interestingly, a lack of consistency in the replication of the symptoms. One or two whacks of WOT would induce it, yet it's possible to go twenty or thirty miles and get nothing.. As far as checking for heat goes, I'd suggest visiting an RC hobby store. They have IR heat detectors ( for checking the head temp when tuning a nitro engine) for about twenty bucks, just make sure a cat wouldn't be off the end of the scale.

Fuel pressure / pump / quality / For sure, this shows the signs of a fuel issue, stumbling, erratic idle, taking time to recover, as if it had to work the bad gas past the injectors, etc. There was one thing that was mentioned that was interesting. That the gas cap, when released, sounded like the doors opening on the Enterprise... The test to see if pressure build up in the gas tank was the issue was simple, just unscrew it a bit and go for a boot.. But that still leaves some unanswered questions .. Why was there so much pressure there in the first place? Is there supposed to be pressure in the gas tank? if so, how much? Where does this pressure come from? What is supposed to limit / regulate it? It was posted that excess pressure in the tank reduced fuel pressure available to the injectors. I would of thought that it would ADD to the pressure at the rails, but Hey!! I know Jack about how that works.. I had hoped that someone who knew more would have commented on that issue, but it didn't happen. Either way, as with the other causes, it exhibits some of the symptoms, but lacks the consistency / timing to be a definitive point of issue (IMHO) Fuel pumps sometimes die outright, sometimes they die slowly... but not THIS slowly. Usually, they give themselves away when they're going slowly by taking longer and longer to work up pressure on start up, as in if you turn on the key, but don't start the car, how long do they go wwhhrrrrrrr, before they reach pressure and stop.

Also, although the post was "won't climb hills".. the hill is on the way home, AFTER it's warmed up.. In five pages of posts, unless I missed something somewhere, it doesn't do it cold. Something is giving up as it gets hot.

So... All that leaves me is that it's a sensor lying to the ECU... The sensor lies, the ECU does what it thinks it should do, and it runs badly. The ECU has one sensor that is it's "go to" sensor. The ECU sets timing, and injector bandwidth based on what it gets from the crank position sensor.

A questionable signal from the crank sensor may make the ECU attempt to compensate, but ... GIGO... There are limits as to what the ECU is capable of

From a brief "" for Crankshaft position failure symptoms...


- Backfiring and Stalling

Your car may stall from time to time. Your car will start fine, but then stall after a time. It can stall a few seconds after starting or quite some time after starting. This goes the same for backfiring. You will notice that the car keeps backfiring frequently.

- Irregular Car Function

Basically you will notice that regular engine workings will start to become irregular, such as speed fluctuations, irregular acceleration, idling fluctuations, and more. If you start to notice a lot of odd and irregular workings then check the sensor.


The good news is that it can be checked with a multi meter, but I don't know if it must be malfunctioning when it's checked, or if it would show as being outside specs regardless.. But, I would suggest checking it when it's hot, as that's when the symptoms manifest themselves.

O.K.... That's it, I'm done. That was my last "Hail Mary". Kudos to all that have posted their thoughts / ideas on this. I meant no disrespect with my dissection of why they weren't "THE" cause. Just why I think there may be a less obvious cause.

But, I'd still like a good explanation / tutorial about the high pressure in the gas tank.

So now I'm going to STFU and wait with baited breath to see what it finally turns out to be.
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  #75  
Old 02-21-2014, 05:41 PM
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Re: SVX can't climb hills

Nice writeup, Chucksta. The one thing that I have been focusing on has been the lack of CEL's if I read the posts correctly(maybe an O2 sensor was mentioned ?).

Would think the crank sensor, coil misfires would be spitting out a code or three...Have you downloaded the stored ECU codes to see if any thing is there of interest ? The fuel source, be it pressure feed or contamination, would be CEL free, I believe. Have the hard fuel lines been visually checked to confirm no pinched areas ? None of my theories really fit 100% the scenario..miles of trouble free driving followed by the hiccups/stalling..mentioned crank sensor failure symptoms match this car as close as anything else I've seen.
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